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81.
Ahmed I. Foudah Sultan Alshehri Faiyaz Shakeel Mohammed H. Alqarni Tariq M. Aljarba Prawez Alam 《Molecules (Basel, Switzerland)》2022,27(13)
The study aimed to develop a new reverse-phase high-performance liquid chromatography (RP-HPLC) method with diode array detection (DAD) detection for simultaneous estimation of escitalopram (EST) and clonazepam (CZP) in tablet dosage forms with a quality by design (QbD) approach. The chromatographic conditions were optimized by Box-Behnken design (BBD) and developed method was validated for the linearity, system suitability, accuracy, precision, robustness, sensitivity, and solution stability according to International Council for Harmonization (ICH) guidelines. EST and CZP standard drugs peaks were separated at retention times of 2.668 and 5.046 min by C-18 column with dimension of 4.6 × 100 mm length and particle size packing 2.5 µm. The mobile phase was methanol: 0.1% orthophosphoric acid (OPA) (25:75, v/v), with a flow rate of 0.7 mL/min at temperature of 26 °C. The sample volume injected was 20 µL and peaks were detected at 239 nm. Using the standard calibration curve, the % assay of marketed tablet was founded 98.89 and 98.76 for EST and CZP, respectively. The proposed RP-HPLC method was able to detect EST and CZP in the presence of their degradation products, indicating the stability-indicating property of the developed RP-HPLC method. The validation parameter’s results in terms of linearity, system suitability, accuracy, precision, robustness, sensitivity, and solution stability were in an acceptable range as per the ICH guidelines. The newly developed RP-HPLC method with QbD application is simple, accurate, time-saving, and economic. 相似文献
82.
References: 《理论物理通讯》2007,47(5):829-834
It has been pointed out by Hall et al. [Gen. Rel. Gray. 28 (1996) 299.] that matter collineations can be defined by using three different methods. But there arises the question whether one studies matter collineations by using LεTab=0, or LεT^ab = 0 or LεT^b a=0. These alternative conditions are, of. course, not generally equivalent. This problem has been explored by applying these three definitions to general static spherically symmetric spacetimes. We compare the results with each definition. 相似文献
83.
84.
M. Tariq Riaz Ivanna Pohorilets Jackson J. Hernandez Jeovanna Rios Nancy I. Totah 《Tetrahedron letters》2018,59(29):2809-2812
A practical, operationally simple preparation of 2-(trimethylsilyl)methyl-2-propen-1-ol derivatives is described. The cobalt catalyzed coupling of a protected vinyl halide with trimethylsilylmethylmagnesium chloride shows excellent functional group tolerance and provides these synthetically useful allyl silanes in good overall yield. By this method, the use of highly concentrated organolithium reagents, complex reaction protocols, and expensive starting materials is avoided. 相似文献
85.
Peng Liu Mohammad Yasir Dr. Albert Ruggi Prof. Dr. Andreas F. M. Kilbinger 《Angewandte Chemie (International ed. in English)》2018,57(4):914-917
Heterotelechelic polymers were synthesized by a kinetic telechelic ring‐opening metathesis polymerization method relying on the regioselective cross‐metathesis of the propagating Grubbs’ first‐generation catalyst with cinnamyl alcohol derivatives. This procedure allowed the synthesis of hetero‐bis‐end‐functional polymers in a one‐pot setup. The molecular weight of the polymers could be controlled by varying the ratio between cinnamyl alcohol derivatives and monomer. The end functional groups can be changed using different aromatically substituted cinnamyl alcohol derivatives. Different monomers were investigated and the presence of the functional groups was shown by NMR spectroscopy and MALDI‐ToF mass spectrometry. Labeling experiments with dyes were conducted to demonstrate the orthogonal addressability of both chain ends of the heterotelechelic polymers obtained. 相似文献
86.
Tariq Aziz 《Pramana》1995,45(Z1):1-31
The Z factory at LEP is like a mini B factory. About 20% of the time a Z decays to a pair of b flavoured hadrons. As a result,
this has provided a major boost to B physics studies. The four sophisticated LEP detectors, with millions of Z events, have
provided a variety of interesting results. Only a snapshot of the major developments can be covered in one review. We have
considered the results related to
coupling, in particular, the measurements of Rb=Γb/Γhad the forward backward charge asymmetry. The b hadron properties, like inclusive and exclusive lifetime measurements are summarised
briefly. Measurements of
oscillation parameter as well as the evidence for time dependent evolution have been discussed. Studies of interesting decay
modes have been mentioned. 相似文献
87.
X-Ray diffraction, infrared, and raman spectroscopic methods were investigated for the detection of K2SO4 in excess of K2S2O7 in solid solutions.The X-ray diffraction lines of K2SO4 were found to be overlapped by the diffraction pattern of K2S2O7 and infrared studies indicated that K2SO4 absorption bands corresponded to regions of strong absorption in K2S2O7. The detection of sulfate could not be carried out by the X-ray diffraction and infrared methods. However, the raman method indicated that a strong and narrow K2SO4 band at 981 cm?1 could unambiguously be used for the detection of sulfate in solid solutions of K2SO4 in K2S2O7, as pyrosulfate showed no absorption around this band. 相似文献
88.
The differential thermal analysis technique was investigated for the detection of K2SO4 in the presence of K2S2O7. It was found that >4% K2SO4 could be detected from an endothermic peak due to K2SO4 at 582 ± 2 °C as the dta profile of K2S2O7 showed no peak in the temperature range of 500–650 °C at 25-μV sensitivity. Mixtures containing <4% K2SO4 could be successfully analyzed by using a sensitivity of 10 μV. 相似文献
89.
Mohammad Wasim Muhammad Daud Mohammad Arif Rameez ul-Islam Sajid Iqbal Yasir Anwar 《Journal of Radioanalytical and Nuclear Chemistry》2012,292(2):653-659
In the under developed countries, the people of far-flung rural areas still depend to a large extent upon herbal medicines.
At the foundation of usage of herbal medicine is the experience of thousands of years. The present paper deals with the characterisation
of exotic fruits for essential and toxic elements. The samples include Morus nigra, Morus alba, Salvadora persica and Carissa opaca (from low and high altitude). Two standardizations of neutron activation analysis, that is, semi-absolute k
0-instrumental neutron activation analysis (k
0-INAA) and epithermal neutron activation analysis (ENAA) were employed for the quantification of elements. The analysis methodologies
were validated by analyzing the IAEA-336 (lichen) and NIST-SRM-1572 (citrus leaves). Sixteen elements including Br, Ca, Cl,
Co, Cr, Fe, I, K, Mg, Mn, Na, Rb, Sb, Sc Sr, and Zn were determined in all samples. Daily intakes of various elements from
the samples were measured and compared with the dietary reference intakes. Additionally, principal component analysis was
performed to extract information regarding samples and elements. 相似文献
90.
Tariq Allie-Ebrahim Qingyu Zhu Geoff D. Moggridge 《Physics and Chemistry of Liquids》2017,55(5):669-673
A correction to the reported liquid–liquid equilibrium parameters using the non-random two liquid (NRTL) thermodynamic model for the ethanol/toluene/n-decane system at 298 K is reported. The parameters were calculated by minimising the residual between the calculated coexistence and the experimental compositions. However, to obtain a physically plausible coexistence curve, a parameter in the NRTL model had to be fixed. This highlights the importance of assessing the entire coexistence curve, as opposed to only comparing the calculated compositions to the experimental data points. This is because undertaking the regression for all the available parameters will result in a smaller residual and better fit of the calculated points to the experimental points. This leads to an apparent improved fit but the complete coexistence curve will show that the parameters are not physically plausible. 相似文献